A switching device using a micro electromechanical system (MEMS) is conventionally known. In such a switching device, connection and disconnection between signal lines is performed using a driving element formed of a piezoelectric element or an electrostatic element, a beam formed of a flexible member that is deformed by a driving element, and a contact terminal attached to the beam.
The MEMS switch can be used for connection of a high-frequency signal, such as an RF signal. In a representative component (hereinafter, a movable unit) in which a beam and a driving element are combined, a contact terminal (an electrode) is provided at a tip of the beam. The beam is accommodated in a housing, and an electrode that is a connection destination is provided at a position facing the contact terminal at the tip of the beam in the housing. Due to vibration of the beam, contact (connection) and separation (disconnection) between the electrode of the beam tip and the electrode of the housing are repeated. A MEMS switch for an RF controls transferring an RF signal through such an operation.
The MEMS switch serves as a switch by repeating contact and separation using a small displacement. However, in a movable portion, a position of a contact relative to a housing is likely to be changed due to stress of a film or thermal stress due to a temperature change. A scheme of installing a signal line on a facing movable portion (see U.S. Pat. Nos. 8,552,621 and 8,604,670) has been proposed as a means for avoiding this problem.